Legend:

The debugger is integrated with GHCi, and it is on by default. The debugger slows program execution down by a factor of approximately XXX times. You can turn it off (to avoid the slowdown) using the `-fno-debug` command line argument.

14

The debugger is integrated with GHCi, and it is on by default. The debugger slows program execution down by a factor of approximately XXX times. You can turn it off (to avoid the slowdown) using the `-fno-debug` command line argument, when you start GHCi.

When a computation has hit a breakpoint it is sometimes useful to continue execution up until the next breakable expression is evaluated, regardless of whether there is a breakpoint set at that location. This functionality is provided by the `:step` command:

158

159

{{{

160

*Main> :step

161

}}}

162

163

The `:step` command accepts an optional argument expression. The expression is evaluated as usual, but the computation will stop at the first breakable expression which is encountered, for example: